Roof module and method of producing a roof module

ABSTRACT

A roof module comprises an outer shell and a foamed inner shell. The outer shell has a rim including an edge of cut and the inner shell extends as far as on the edge of cut. There is also proposed a method of producing such a roof module.

TECHNICAL FIELD

[0001] The invention relates to a roof module comprising an outer shelland a foamed inner shell. The invention further relates to a method ofproducing such a roof module.

BACKGROUND OF THE INVENTION

[0002] Hitherto, the roof module has been produced by placing the outershell, the rim of which is configured with an excess width, into afoaming mold and subsequently applying the inner shell onto the innerside of the outer shell by foaming. In the process, the inner shellextends as far as to the rim of the outer shell. After foaming, the rimof the outer shell together with the inner shell applied by foaming iscut to size. Cutting to size of the outer shell provided with the innershell is a difficult operation during which a lot of dirt occurs.Moreover, that part of the inner shell which is on the cut-off rims ofthe outer shell, represents cuttings, this increasing the productioncosts. Finally, the roof module has exposed edges of cut after it hasbeen cut to size.

[0003] It is the object of the invention to improve a roof module of thetype initially mentioned as well as a method of its production to theeffect that fewer cuttings and, hence, lower production costs areproduced and that the roof module does not have edges of cut which areexposed.

BRIEF SUMMARY OF THE INVENTION

[0004] According to the invention, a roof module is provided whichcomprises an outer shell and a foamed inner shell. The outer shell has arim including an edge of cut and the inner shell extends as far as onthe edge of cut. Such a roof module may be obtained by the followingmethod: firstly, an outer shell is made available. Then the rims of theouter shell are cut to size. As a next step, the outer shell is placedin a foaming tool and a curable material is applied onto the outershell. Subsequently the foaming tool is closed, a seal in the foamingtool pressing against the rim of the outer shell from outside towardsinside. The curable material hardens, it reaching the edges of cut onthe rim of the outer shell. The roof module produced in this way doesnot have to be cut to size after the foaming operation. Consequently,only so much of the material for the inner shell has to be introduced asis actually required for it; no loss occurs. As the inner shell extendsas far as on the edges of cut at the rim of the outer shell, the edgesof cut—which have been produced prior to foaming on cutting the outershell to size—are sealed.

[0005] According to a preferred embodiment it is provided for that theouter shell is configured with an undercut on its rim. This can beobtained in that, on producing the roof module, the seal is pressedelastically against the outer shell when the foaming tool is beingclosed and plastically deforms the outer shell in this process. It isnot required in this procedure to provide slider elements in the foamingtool which usually are required for producing the undercut on foaming.It is not required either that the outer shell has the undercut alreadybefore foaming. This, in fact, could be managed during production of theouter shell only with large expenditure.

[0006] Advantageous designs of the invention will be apparent from thesubclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007]FIG. 1 shows in a broken sectional view a foaming tool in the openstate, with an inserted outer shell according to a first embodiment;

[0008]FIG. 2 shows the foaming tool of FIG. 1 in the closed state, aninner shell being applied to the outer shell by foaming;

[0009]FIG. 3 shows a detail of FIG. 2 on an enlarged scale;

[0010]FIG. 4 shows in a broken sectional view a foaming tool in theclosed state, with an outer shell and an inner shell applied by foaming,according to a second embodiment; and

[0011]FIG. 5 shows a detail of FIG. 4 on an enlarged scale.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0012] In FIGS. 1 to 3 there is schematically shown a foaming tool 10which consists of an upper part 12 and a lower part 14. Received in thelower part 14 is an outer shell 16 which will be a part of the roofmodule and which may consist of aluminum or plastics, for instance. Theouter shell 16 has a rim 18 that ends at an edge of cut 20. The edge ofcut is produced in the course of cutting the outer shell 16 to size.

[0013] In the lower part 14 of the foaming tool 10, there is received aseal 22 which has a base section 24 anchored in the lower part 14 and ahead section 26 associated to the rim 18 of the outer shell 16. The seal22 is made of a material which on the one hand has sufficient resistanceto pressure and temperature with regard to the foaming operation andwhich is elastically deformable, on the other.

[0014] The upper part 12 of the foaming tool 10 has a sealing sectionassociated to the rim 18 of the outer shell 16 and the head section 26of the sealing 22. The sealing section consists of an end surface 30 anda pressure surface 32. The end surface 30 extends approximatelyperpendicular to the direction along which the upper part 12 and thelower part 14 of the foaming tool 10 are movable relative to each other.The pressure surface 32 extends obliquely to the end surface.

[0015] When the foaming tool 10 is transferred from the open positionshown in FIG. 1 into the closed position shown in FIG. 2, the obliquelyextending pressure surface 32 engages the head section 26 of the elasticseal 22 and moves this head section to the left due to a wedge effect.In so doing, the rim 18 resting at the head section 26 of the seal 22 islikewise moved to the left. When the foaming tool is in the closedstate, the end surface 32 rests tightly on the upper side of the headsection 26 of the seal 22. The edge of cut 20 of the rim 18 of the outershell 16 lies opposite the end surface 30 at a small distance (see inparticular FIG. 3).

[0016] Prior to closing the foaming tool 10, there has been applied ontothe outer shell 16 a foamable material which cures when the foaming toolhas been closed, so that it forms an inner shell 34 on the inner side ofthe outer shell 16. As can be taken in particular from FIG. 3, the innershell extends along the rim 18 as far as on the edge of cut 20 which iscovered by the material of the inner shell 34. In the region where thematerial of the inner shell 34 rests at the head section 26 of the seal22, namely between the edge of cut 20 of the outer shell 16 and the endsurface 30 of the upper part 12 of the foaming tool, the inner shellextends away from the edge of cut in extension of the outer surface ofthe outer shell. The material which is present there, seals the edge ofcut 20. As the head section 26 of the seal has moved the rim 18 of theouter shell 16 towards inside on closing the foaming tool, the rim 18 ofthe outer shell 16 rests at the head section 26 of the seal 22 with asufficiently high force, so that the material of the inner shell 34 cannot enter the region between the rim 18 of the outer shell 16 and thehead section 26 of the seal 22 and, hence, can not emerge from thefoaming tool. With this, the rims of the roof module formed by the outershell 16 and the inner shell 34 are smooth after foaming, without theneed of a subsequent cutting operation.

[0017] In FIGS. 4 and 5 there is shown a roof module according to asecond embodiment. The same reference numerals will be used for thecomponents known from the first embodiment, and reference is made to theabove explanations.

[0018] The difference between the first and the second embodiment isthat in the second embodiment the pressure surface 32 is inclined more,so that upon closing the foaming tool the head section 26 of the seal 22is moved to the left to a greater extent. In the process, the rim 18 ofthe outer shell 16 is moved to the middle of the outer shell 16 so farthat the outer shell is undercut, i.e. the edge of cut lying furtherinwardly than does the rim 18 in the region of the transition to thehorizontally extending middle section of the outer shell 16. Thedeformation of the rim 18 on closing the foaming tool is preferably aplastic one, so that after opening the foaming tool only a slightspring-back occurs which does not impose an exceed load on the fit ofthe inner shell 34 on the outer shell 16. It is e.g. in the region ofthe rear flap of a vehicle provided with the roof module where theundercut can be of advantage.

1. A roof module comprising an outer shell and a foamed inner shell,said outer shell having a rim including an edge of cut and said innershell extending as far as on said edge of cut.
 2. The roof moduleaccording to claim 1, wherein said inner shell extends away from saidedge of cut in an extension of an outer surface of said outer shell. 3.The roof module according to claim 1, wherein said outer shell isconfigured with an undercut at its rim.
 4. A method of producing a roofmodule comprising an outer shell and a foamed inner shell by means ofthe following steps: an outer shell having a rim is made available; saidrims of said outer shell are cut to size; said outer shell is placed ina foaming tool; a curable material is applied onto said outer shell;said foaming tool is closed, a seal in said foaming tool pressingagainst said rim of said outer shell from outside towards inside; saidcurable material hardens, it reaching said edges of cut on said rim ofsaid outer shell.
 5. The method according to claim 4, wherein said sealis pressed elastically against said outer shell when said foaming toolis being closed.
 6. The method according to claim 5, wherein said sealplastically deforms said outer shell when said foaming tool is beingclosed.